Cooling container

ABSTRACT

A transportable refrigerating container including descending passage means operable to receive a gravity induced flow of coolant gas and having flow controlling aperture means providing individualized, controlled communication between the descending passage means and individual product compartments.

United States Patent 1 1 Frank et a1.

1 Feb. 18, 1975 1 COOLING CONTAINER [75] Inventors: Karl Frank,Linz/Rhine; Martin A.

Frank, Cologne; Dieter Tschentscher, Mayen, all of Germany [73]Assignee: Firma Burger Eisenwerke Aktiengesellschaft, Burg/Dillkreis,Germany Filed: June 4, 1973 Appl. No: 366,279

[30] Foreign Application Priority Data June 5, 1972 Germany 2227313 [52]US. Cl 62/382, 62/388, 62/420, 62/441, 62/457 [51] Int. Cl. F25d 25/02[58] Field of Search 62/384, 388, 382, 457,

[56] References Cited UNITED STATES PATENTS 1,883,940 10/1932 Killeffer62/388 1,922,456 8/1933 Powell 1,963,674 6/1934 Pearsons.. 2,325,3717/1943 Clerc 2,506,448 5/1950 Gregor 62/382 Primary Exunziner-MeyerPerlin Assistant I;'.\'uminerRonald C. Capossela Attorney, Agent, orFirmBurns, Doane, Swecker 8L Mathis [57] ABSTRACT A transportablerefrigerating container including descending passage means operable toreceive a gravity induced flow of coolant gas and having flowcontrolling aperture means providing individualized, con trolledcommunication between the descending passage means and individualproduct compartments.

17 Claims, 15 Drawing Figures PATENTEQ FEB l 8W5 sum 2 OF 3.

1 COOLING CONTAINER GENERAL BACKGROUND, OBJECTS, AND

SUMMARY OF INVENTION The invention relates to a refrigerating containerto keep temperature sensitive products, such as food, pharmaceuticals,chemical products, etc., fresh and cool. Particularly, the inventionrelates to a transport- I able container having a work space subdividedin several chambers to receive the goods to be refrigerated and acompartment for a gasifying coolant, especially CO in solid form (dryice). Preferably, this latter compartment is located above said workspace.

For keeping temperature sensitive products cool and fresh, movablecontainers are used today in which the cooling system consists of addedconsumable coolants. Beside nitrogen and freon, carbon dioxideespecially comes into consideration as a consumable coolant here. Ingaseous form, carbon dioxide is heavier than air and in solid form atstandard atmosphere pressure, in its own gaseous atmosphere has atemperature of 78.5C. This solid CO called dry ice, sublimates, i.e.,

it passes from a solid to a gaseous state, whereby at atmosphericpressure with the gas heating to C of the neighborhood, 152.4 K. cal/kgare withdrawn.

Heretofore, this coolant is placed in the container, in the case of theknown containers of the initially mentioned construction, in the form ofprismatic slabs (plates) together with the material to be cooled, or itis arranged compactly above or beside the work space. This, however;results in the essential disadvantage that the cooling stream of gasfills the work space in an uncontrolled manner and that the temperaturepattern developing in the work space is very uneven, in such a way thatat certain places very low temperatures prevail, with the consequence oflocal freezing of the chilled goods, while at other places no sufficientcooling is assured. These disadvantageous effects occur at an increaseddegree, when using containers in air traffic, especially during thestarting and landing phases of the airplanes which cause considerableinclinations of the containers.

To this it must be added that, particularly in air traffic, veryvariable ambient conditions may occur. In case ofa modern airport withcold storage, the required quantity of dry ice is added to the filledcontainer which is at a temperature of l2-l 6C upon leaving the coldstorage. The quantity of coolant is here dimensioned such that thechilled goods remain chilled until served on the airplane. If, however,there is no cold storage at the airport, then such a quantity of dry icemust be added to the container after it being filled, such that the dryice will be capable of cooling down the container itself and itscontents from ambient temperature to, for example, cold storagetemperature and to maintain this temperature of 12l6C until time forserving. From these variable possibilities of use and requirements thereresult, however, variable refrigerating problems, with which thecustomary containers cannot cope.

It is the task of the invention, therefore to create a cooling containerof the initially mentioned type, in which the cooling stream of gasflows controlled in such a way, that the temperature field pattern inthe work space of the container will be as even as possible, even underunfavorable circumstances. as the beginning of cooling, repeated openingof the container door, tipping and sloping movements of thecontainer,etc.

A further task of the invention consists in creating a container whichwill cope with the stated variable con dition, whereby the degree offilling of the container with chilled goods and possibly alsorequirements of the chilled goods for variable cooling needs are stillsuperposed as additional conditions.

According to the invention the solutio of these problems ischaracterized by at least one descending shaft (passage means) branchingoff from the coolant space, for receiving the developing cooling gas,and from which shaft openings (i.e., apertures), dividing the stream ofcooling gas doseably or in segments into partial streams, branch Offinto the individual work space compartments.

In the invention one will insure that the cooling stream drops down in adefined direction of flow in the descending shaft by the action ofgravity, whereby a partial stream is branched off for each compartmenthaving chilled goods and which can be closed exactly with a branchstream or segment which is adequate with respect to its coolingperformance. Detailed experiments have shown that in this manner an eventemperature field pattern quickly occurs in the container which isessentially independent of outside influences such as inclinations ofthe container during take-off of the plane in which the container islocated. Beyond that, however, there also is the possibility, ifdesired, to produce temperature field patterns which are even withinthemselves but variable among each other, for instance, whenever chilledgoods with variable cooling needs are placed in the container.

A further development of the invention concerns a cooling container withinserts arranged in levels one above the other, the topmost levelserving for the coolant, especially in a movable container for keepingfood in airplanes fresh and cool. Such containers, mostly calledtrolleys, are developed according to the invention in such a way thatthe descending coolant gas shaft, preferably extending over the entireheight of the container and across one side or end of the device, islimited by an outside wall of said container and by a separating wallessentially parallel to the former, whereby the separating wall hassluice-like openings leading to the insertable levels of the work space.

If this container has only one door, then the descending shaft can bedisposed on the container side opposite to the door, and the gap spacebetween the door and insertable shelves can have escape openings forexcess air and/or cooling gas, possibly in the form of leaks of the doorhinges. In this way one will achieve a particularly exact guidance ofthe streams of cooling gas and especially the development of an eventemperature field at the beginning of cooling will be accelerated, at atime when the container is still filled with air.

In order to ensure that the desired pattern or direction of flow, evenin case of greater inclinations of the container, the insertions for thecoolant can be slightly slanted toward the horizontal in such a way thatit slopes toward the inlet for the descending shaft.

In the case of cooling containers with doors at two opposed sides, thearrangement advantageously is made such that two descending shafts areprovided on opposed sides of the container and that at least one of thegap spaces, located between the other two container sides and theinsertion levels or goods areas, has escape apertures for excess airand/or cooling gases, possibly in the form of leaks of the door hinges.Further, the descending cooling gas shafts can also be dis posed on bothsides of the container, in which case it will be particularly effectiveto develop the doors on their sides with double walls, and to use thetwo walls of each door as boundaries for the descending shaft. Thesecontainers with descending shafts at opposed sides of the container areparticularly insensitive -with regard to the temperature field patternto inclinations and tippings of the container.

In order to facilitate the controlled, segmented flow or division of thecooling gas stream into partial streams, the apertures in the separatingwall or walls can be designed in such a way that they consist of perforations of the separating wall and of guide tongues or bafflesassigned to the individual apertures and projecting from the separatingwall into the descending coolant gas shaft. Advantageously, theapertures will have widths of passage which are variable amongthemselves, in such a way that the cross section increases from thetopmost to the lowest inserting shelf, whereby the width of passage isdetermined by the cross section of the aperture and/or the position ofthe tongue. With that one will achieve that the cooling effect over theentire height of the container will be as even as possible.Nevertheless, it will not be possible to prevent completely, thephenomenon that in the topmost shelf for chilled goods, which isadjacent to the insert with the coolant, the temperature will droplower, particularly during the period of the start of cooling. This maybe desirable in some cases, perhaps whenever edible ice (ice cream) isto be stored in the topmost level. Whenever the same temperature isalways wanted in the topmost insertion shelf as exists in the lowershelves below it, then according to the invention, the aperture of thetopmost insertion shelffor chilled goods adjacent to the insert forcoolants, can be provided with a closing lid and this insertion shelfcan have closable apertures leading outside.

It has proved to be particularly effective whenever, in the case ofthecooling container according to the invention, dry ice in form of a heapof dry ice tablets, little rods or cubes is used as coolant. This formof the dry ice, as compared to the customary solid dry ice slabs, has aconsiderably larger evaporation surface. This is of particularimportance especially for the abovementioned cooling containers in airtraffic since, there, mostly only relatively short cooling times arerequired.

In a further development of the invention, provision is made such thattwo longitudinally extending walls of a container are developed asguides for the cooling gas in the form, each time, of several flatchannels whigih are connected on the one hand with the compartment forthe coolant and on the other hand with the work space compartments,located at various horizontal levels, whereby the cross section ofpassage of the channels is proportional to their length.

In case of this further development therefore, the stream of cooling gasis divided in partial streams and is fed to the individual work spacecompartment such that the inflowing quantity ofgas is largelyindependent of inclinations of the longitudinal sides of the container,which are generally pointing in the direction of flight. Since guidanceof the cooling gas takes place at both longitudinal sides, the stream ofcooling gas must pass through relatively short paths in order to fillthe space between two adjacent goods levels, i.e., the coolant space forone goods area.

In order to adapt the cooling effect furthermore to the variousconditions on the airport, the insertion of the coolant is developedespecially according to the invention as hereinafter described andclaimed. Especially, insertion of the coolant is subdivided intoshelves, which house the quantity of coolant required for the pertinentcooling task, whereby a heap of small dry ice rods is usedadvantageously, since such a heap has a larger surface than the dry iceslabs of the same weight and thus the quantity of cooling gas sublimatedin the unit of time is larger.

DRAWINGS In the drawings, embodiments of the invention are shown by wayof example, namely:

FIG. 1 shows a cooling container in longitudinal section; FIG. 2 is aperspective. fragmentary view of a separating wall of the FIG. 1container showing sluice openings;

FIG. 3 is an end view ofa separating wall of the FIG. 1 container;

FIG. 4 shows a section through the separating wall of FIG. 3 as providedwith automatically adjustable guide tongues;

FIG. 5 is a longitudinal section up to the axis of symmetry M/N, ortransverse median plane, through a prior art coolant trolley ofcustomary design;

FIG. 6 is a half segment of a trolley, modified, as in the invention,with FIG. 6 being a view showing a section plane AB oriented in aperpendicular plane and extending along the longitudinal axis;

FIG. 7 shows the plane AB from FIG. 6, with half a side wall exposed;

FIG. 8 shows, in a section format, the arrangement of the cooling insertwith the guidance of the cold stream as incorporated in the trolley ofFIG. 6;

FIG. 9 is an internal elevation view of the cooling gas channels in theside wall of the trolley of FIG. 6;

FIG. 9A is a transverse sectional view of the cooling gas channelsdepicted in FIG. 9;

FIG. 10 is a fragmentary top plane view of the cooling insert of theFIG. 6 trolley provided with transverse divisions or longitudinallyspaced functional coolant zones;

FIG. I1 is a fragmentary, further enlarged view of FIG. 10, showing thecooling insert with details;

FIG. 11A is a sectional view taken along the plane CD in FIG. 11; FIG.11B is a sectional view taken along the plane E-F in FIG. 11A; and

FIG. 12 shows a special embodiment of a layer for absorbing thecondensate and additionally insulating the inside space against thecooling insert.

DETAILED DESCRIPTION In the embodiment shown in FIGS. 1 to 4, we aredealing with a so-called trolley, therefore a mobile container forprepared food, as used in airplanes. Here the requirements for coolingperformance are particularly high, because within a limited time, and inconsideration of the least possible weight of the device itself and itscharge ofcoolants, a heterogeneous combination of foods as to quantityand type must be kept cool in an environment mostly of 24C., with theentire system being also subject to movements, for example, at startingof the plane.

FIG. 1 shows such a container in longitudinal section, in which thechilled goods 12 are kept on parallel flat shelves 11 and the dry ice 14is disposed on the topmost shelf 13, the cooling insert. A door islocated in this container at its left end, as viewed in FIG. 1. Thiscooling insert is connected on one narrow side or end of the containerby means of a gap 15 with the work space of the shelves, in a manner yetto be described.

For thermal screening of the work or goods space against the coolinginsert 13, an insulating plate (board) 16 has been provided, which doesnot impede the gap 15. Another insulating plate 17 curbs the heattransfer of the environment through the covering surface 18 of thecontainer.

In order to guide the cooling stream, the entire container (includingshelf 13) in this example has been inclined relative to the horizontalby about 2, so that the cold CO gas developing in the cooling insert 13will reach the gap 15 on account of its specific gravity being 1.5 timesgreater than that of the air still in the work space. This inclinationof the entire container is possible in case of the selected embodiment,since the contents to be cooled are not liquid in open bins(containers). Naturally the same effect could also be achieved by thefact that only the cooling insert has such an inclination, the chilledgood inserts on the other hand being disposed horizontally.

A gate slit 25 is located at one end of shelf 13 and is followed by adescending shaft 21. Shaft 21 is defined by the narrow side (i.e., end)wall 19 of the device and a separating wall 20, parallel thereto. Thecold stream in shaft 21 sinks to the bottom because of gravity. Thiscold descending stream can emerge from the shaft 21 through sluice-likeapertures 22 which communicate with the work space between the shelves.

These sluice openings consist, according to FIG. 2, of perforations ofthe separating wall and of guide tongues 23. These tongues are shown incase of the FIG. 2 embodiment simply by a rectangle constituted by threecuts and a bent edge, each tongue being bent into the inside of thedescending shaft 21 and facing up wardly in an inclined or bafflemanner.

Naturally other geometric forms are also possible for the guide tongues,and their position in the descending shaft 21 can be flat or arched. Ithas furthermore been recognized that the descending shaft 21, at itslowest point, may be connected by apertures (which are not shown in thedrawing) with the work space, so that condensate can emerge into thelatter.

According to FIG. 1 and FIG. 3, these sluice apertures, except for theopening of the insert of the topmost chilled goods shelf which isconnected with the descending shaft 21 by way of a slit 24, are providedfor each of the chilled goods shelves, in such a manner that theeffective width of passage means for emergency of the partial coolingstream into the shelves becomes larger with growing distance oftheshelves from gap 15. The projection of the aperture in the direction ofthe cooling stream is to be understood here as the width of passage.This width of passage is here defined therefore by the effective size ofthe mouth of flow capacity of each such passage in chute 15 as governedby width and/or height of the guide tongue and the bending angle a inFIG. 2. Preferably the arrangement of FIG. 3 is to be selected, in whichthe sluice apertures 23 are disposed, displaced in the direction of thecooling stream and, as can be recognized, the opening angle a grows withthe distance from the gap 25 and with it the above-mentioned width ofpassage. The increase in the size of the opening angle, in addition toincreasing passage mouth size, tends to minimize the extent to whichupper baffles 23 might shield" lower baffles 23 and impede flow intotheir associated passages.

It is furthermore essential that the baffle plate which constitutes theslit 25, and which runs across the entire width, screen the slit 24,which represents the connection of the uppermost shelf for chilled goodswith the descending shaft 12. The reason for this is to avoid a toosevere drop of temperature in the topmost cooling shelf. For the samepurpose, bores or vents 26 are provided in the topmost cooling shelf,which lead into the open.

Each of the aperture means 24 and vent means 26 may be provided withselectively manipulatable closure means operable to selectively open(partially or fully) or close these openings.

The cooling container as in the invention can be filled in the customarycooling space at, for example, 6C. with food dishes of this temperature,and then be charged with dry ice and put to use. By the inclination ofthe container or the shelf 13, a path leading by gravity into thedescending shaft 21 and through the sluice apertures 22 into the workspace is forced upon the heavy CO gas. After a relatively short time aneven temperature field pattern develops in the container, as a result ofthe distribution of the Sublimated dry ice according to the invention.The required pressure balance or differential takes place via the leaksin the doors of the container and through the abovementioned small bores26 in the opposed long container walls between cooling insert anduppermost chilled goods shelf. By the arrangement of the bores 26precisely at this spot, the most endangered topmost chilled goods shelfwill be protected against freezing of the chilled goods.

It is apparent from FIG. 4 that, by the further development of theinvention, an automatic control for the closing of the cooling stream byinfluencing the width of passage of the sluice openings 22 and thus ofthe partial cooling stream to the chilled goods shelves can be provided.In this connection, a rod 27 is provided which is connected on the onehand with the housing of the container and on the other hand with onemovable guide tongue or baffle 30 and which moreover has a largetemperature expansion coefficient. This rod 27 deflects the tongue 30,which is connected via a swivel joint or pivot connection 28 with theseparating wall 20. The deflection is accomplished in such a way that incase of too much cooling the rod 27 contracts and the effective crosssection or mouth size of passage of the sluice apertures is decreased.In case of too little cooling, the rod expands and this mouth size isenlarged. With the aid of the coupling rod means 29 it is possible tooperate the sluice openings of several adjacent levels in the manner oflevers by a single adjusting rod 27.

Naturally, the embodiment shown can have numerous modifications.

Thus, the invention can also be realized in case of containers with twodoors at the two narrow sides (ends), by making the latter with doublewalls and by developing the inside walls of the doors as separatingwalls with baffle plate 25 and sluice apertures 22. In case of thisembodiment, the function of the cooling stream depends even less on theinclination of the container. At a precisely horizontal position, thesame quantity of cooling gas flows through the two descending shaftsrunning on each end, inside the doors, and emerges through the sluiceopenings from both sides in the work space. The inflow of the coolinggas into the descending shafts can be facilitated still more by thecoolant insert being buckled or bent in such a way that it slopes onboth ends toward the inlet slits 25.

Furthermore, the invention is not only limited to the described movablesmall containers, but it can also be used in case of stationary largecontainers, perhaps the well-known container in the so-called iglooconstruction. It is always essential in this case, however, that thedeveloping cooling gas is guided as a homogeneous cooling stream with adefinite direction of flow and that it is then doseably distributed tothe individual chilled goods compartments.

For the explanations of the modifications of the invention according toFIGS. 6 to 12, first of all, a trolley of customary construction will bedescribed on the basis of FIG. 5. In the FIG. arrangement, the insidetrolley space is divided in parallel planes 110 for the reception of thechilled goods 111. Above the topmost work plane is the cooling insert112 with the dry ice 113. The stream of cooling gas drops, in this case,through a slot 114 along the door, without guidance, downward wherebyeither the left (or right) side is acted on more or less by the coolinggas as a result of the inclination and thus an undesirable, variablecooling is brought about at the sides of the door.

According to the invention the container now is developed according toFIG. 6 in such a way that the stream of cooling gas is fed under controlinside the long side walls 115 to the spaces between the planes 110which are to be cooled. The arrangement of the channels for controllablycarrying the streams of cooling gas, according to FIG. 7 as shown by cutAB made longitudinally of the trolley, with the channels exposed to theright of exposure line VT, is made such that, with due consideration ofthe flow resistance, the channels leading to the lower planes, forexample, 116 and 117, are developed broader than those which supply theupper planes, for example, 118, and that the broader channels arelocated on the sides of the door. (i.e., the channels on the right sideofline VT would be a mirror image of the channel arrangement on the leftside.)

One example for the guidance of the cooling stream in the side wall isshown in FIGS. 8, 9 and 9A.

The shaped side wall 115 (in sandwich type construction) has on itsinside the channels, for example, 116, 117, 118, already described. Inthe inside wall 119, deep-drawn supports 120 for the planes 110(inserts) have been developed. A part of at least some of these supportshas outlet slits 121 on their underside for the cooling gas, and theyare adapted in size to the width ofthe channel, i.e., the wider thechannel, the wider the slit associated therewith. In the upper planesthere are small discharge slits, since there the cold radiation of thewalls suffices for the cooling. There also is an insulating layer 122applied to the wall in order to dam up or limit the cold radiationthrough the wall itself.

For reinforcement of the walls 119 at about half the height, a planesurface connected detachably with the wall elements 119, and not shown,may be provided.

In order to make possible a thorough cleaning of the trolley, the insidewall 119 can be removed.

The molded part 123, closing the trolley on top, houses the coolinginsert or drawer 124 in which is located the dry ice 113. In the FIGS.10 11,11A, and 11B and via the cuts or sections CD and EF, this coolinginsert 124 is shown in detail.

FIG. 10 shows half the insert with its axes of symmetry P/Q(longitudinal) and R/S (transverse). The loading surface for the dry iceheap has been transversely divided by continuous transverse strips 125and discontinuous longitudinal strips 126 into partial surfaces in sucha way that, depending on the intended duration of cooling, the entirespace of the cooling insert or partial spaces are filled with dry ice.The dry ice itself rests on a perforated bottom 127 on which there areformed continuous strips 129. As shown in FIG. 11, supporting rails 128may support tray means 127. Up to certain inclinations of the device,the strips on ribs 129 will prevent the heap of dry ice from slippingduring the starting phase of an airplane. The above-mentioned strips 129thus serve as holding and isolating strips and may be at least partlyadjustable and/or variable in height.

The connection of the cooling insert with the channels in the lateralwalls is accomplished by openings 130. Between each two adjacentapertures there is each time a rail 128, which rail tends to cause equalquantities of cooling gas to flow downwards through all the openings 130even at an inclination of the trolley, as shown by lines X/X. The tstraight line Y/Y can be drawn just the same, which refers to a dry iceretention slope as provided by strips 125. The oblong holes 130 can beof different lengths, in accordance with the width of their associatedchannels in the side walls.

As this juncture, it will be recognized that the FIG. 6-11B embodimentis a species of the FIG. 14 invention, with the spacebetween 124 and 127providing a descending chute, branching off of which are centralapertures 11 6, 117, 118.

The insulation 31 (FIG. 8) located on the underside of the coolinginsert is of particular significance in order to prevent anyundercooling of the topmost shelf or of the highest shelves by too greata degree of cold radiation through the base of the dry ice container.

In the first cooling phase, the heavy cold CO gas presses the air in thecontainer upwards, and through leaks of the container into the open air.Water vapor condenses from this air and is deposited mainly on theinsulating layer as a top limitation of the space, and iinally dripsonto the chilled goods of the topmost shelf and generally defaces theirappearance and value. The invention provides for an additionalinsulating plate 132 to be attached below the insulating layer 131firmly connected with the molded piece 123, the raw material of saidplate 132 being permeable and permitting water vapor to pass through,but absorbing droplets of fog and holds them, whereby the originallygreat heat resistance of the raw material is reduced by the waterabsorption. At the outset, the lowest layer of the insulation 132 with a0C.-isotherm will constitute a cold brake or thermal barrier. Theincrease of the heat conductivity of this layer with the waterabsorption, which occurs during the cooling process in its first phase(the sublimation temperature of the dry ice does lie considerably lowerin atmospheric air than a pure CO 2 atmosphere), serves to permitconductive cooling of the upper goods compartment while avoiding thermalshock due to a too abrupt cooling action at the outset. In other words,thermal shock due to excessive conductive cooling through layer 132, atthe outset, is avoided, but such conductive cooling is graduallyimplemented as the thermal conductivity of layer 132 increases.

This insulating layer 132 can be produced for example by a fabric ofplastic, for example, PVC, which after use in a container is removed anddried and is removed after repeated use for hygienic reasons.

A further embodiment of barrier 132 is shown in FIG. 12, where a bag 134of special cellulose which absorbs or binds water is stretched across aresilient, U-shaped clip 133. A holding device 135 secures thisassembly. The 134 bag is detached from clip 135 and thrown away afteruse and, since it consists of cellulose, is simply burned.

According to this example the dry ice is housed in a sliding drawer 124which, for the purpose of being charged, is pulled out of the moldedpiece 123. In order to simplify the charging process, and in order touse dosing aggregates for the quantities of dry ice required for thecooling task, and in order to be able to accomplish the charging inseries or on the conveyor, the top covering 135 may be developed as atightly closing lid (not permitting any admission of air), which isswivelably articulated by a hinge 136.

If there is any desire to produce lower temperatures in the space of thetop level, for example, for the storage of'ice cream, etc., then adirect gas connection to the cooling insert and to this space must beestablished by one or more closeable and in one dimension cntrollableapertures, possibly communicating with channel means such as 118, butwhich are not shown.

SCOPE OF INVENTION In describing the invention, its principal advantageshave been delineated and made apparent, and a variety of structural andfunctional modifications have been noted.

Those skilled in the refrigerating art and familiar with this disclosuremay recognize other additions, deletions, substitutes, or othermodifications which would be deemed to fall within the scope of theinvention as set forth in the appended claims.

What is claimed is:

1. In a transportable cooling container adapted to keeptemperature-sensitive products, such as food and pharmaceuticals, coolduring transportation thereof and having a work space subdivided intoseveral vertically spaced product compartments for the cooled productsincluding an uppermost product compartment a coolant compartmentdisposed above said product compartments, there being a tendency duringtransportation of said container for the compartments to becomeprogressively warmer relative to a downward direction of reference; theimprovement comprising:

at least one passage means descending from the coolant compartment andadapted to receive a gravity flow of gasified coolant; and

a plurality of vertically spaced apertures branching from the descendingpassage means and individually communicating with individual ones ofsaid product compartments;

the sizes of the inlet mouths of said apertures increase progressivelyrelative to a downward direction of reference such that said aperturesdivide said gravity flow of gasified coolant into increasingly largerportions relative to a downward direction of reference, to maintain thetemperatures of said product compartments substantially uniform. 2. Acooling container as described in claim 1 wherein:

an upright baffle plate is located at an upper portion of saiddescending passage means and is operable to provide a constrictedentrance into the uppermost product compartment.

3. A cooling container as described in claim 1 wherein:

said descending passage means, at its lower end, and

at a location shielded from said apertures, is operable to collect anddrain condensate.

4. A cooling container as described in claim 1 wherein:

said coolant comprises particuted, solidified carbon dioxide.

5. Apparatus according to claim 1 wherein said transportable coolingcontainer has support wheels, side walls, and front and rear ends spacedin the direction of container travel; said passage means extendinglaterally across and vertically along said rear end; at least part ofsaid coolant compartment being inclined relative to horizontal towardsaid descending passage means to facilitate gravitational flow ofcoolant gas thereto; the apertures disposed beneath the uppermostproduct compartment including guide tongues extending outwardly andupwardly from their respective com- 35 partments and into saiddescending passage means; the horizontal locations of saidtongue-including apertures being generally staggered relative to avertical direction of reference to minimize the extent to which the flowof cooling gas into said apertures is impeded.

6. A cooling container as described in claim 1 wherein:

said descending passage means extends essentially over the entire heightof the container and reaches across one side of the container;

said descending passage means is bounded on one side by an outside wallmeans of the container and on another side by a separating wall meansextending essentially parallel to the outside wall means;

and

said separating wall means has sluice-like apertures,

each leading to an individual product compartment. 7. A coolingcontainer as described in claim 6, wherein:

said sluice-like apertures comprise openings in the separating wallmeans and guide tongues extending from individual apertures andprojecting from the separating wall means into the descending passagemeans at progressively greater angles of inclination along a downwarddirection of reference. 8. A cooling container as described in claim 7,wherein:

said container includes a door, located on a narrow side of saidcontainer; said door being operable relative to said compartments; saiddescending passage means is disposed on a side of said containeropposite said door; and said descending passage means is disposed incommunicating relation with vent means communicating with the exteriorof said container.

9. A cooling container as described in claim 8, wherein:

said coolant compartment supports a coolant inclined in relation to thehorizontal in such a way that it slopes downward toward said descendingpassage means.

10. A cooling container as described in claim 9, wherein the entirecontainer, including said coolant and product compartments, has adownward slope, inclined downwardly toward said descending passagemeans.

11. A cooling container as described in claim 1 wherein:

said descending passage means comprise shaft means provided on oppositeends of the container; and at least an upper one of said productcompartments includes vent means communicating with the exterior of saidcontainer and located on sides of said container extending between saidnarrow sides.

12. A cooling container as in claim 11, wherein:

said coolant compartment supports coolant inclined downwardly towardrespective ones of saidshaft means to facilitate gravitational flow ofsaid cooling gas toward said respective shaft means.

13. A cooling container as described in claim 12, wherein:

each of said shaft means is defined, at least in part,

by spaced wall means of door means of said container.

14. A cooling container as described in claim 1 wherein:

an aperture communicating with the uppermost product compartment may beselectively closed; and

said uppermost product compartment is operable to be selectively ventedto the exterior of said container.

15. A cooling container as described in claim 14,

wherein:

said container includes an insulating plate disposed between saiduppermost product compartment and said coolant compartment.

16. A cooling container described in claim 1 including:

movable closure means for said apertures located beneath the uppermostproduct compartment; coolant flow control means operable to operate saidclosure means to control flow of gasified coolant through said aperturesin response to the temperatures of the respective product compartmentcommunicating with said aperture.

17. A cooling container as described in claim 16,

wherein:

a plurality of said closure means are interconnected such that saidcoolant flow control means is operable to simultaneously control theflow of gasified coolant through said plurality of said apertures.

1. In a transportable cooling container adapted to keeptemperature-sensitive products, such as food and pharmaceuticals, coolduring transportation thereof and having a work space subdivided intoseveral vertically spaced product compartments for the cooled productsincluding an uppermost product compartment a coolant compartmentdisposed above said product compartments, there being a tendency duringtransportation of said container for the compartments to becomeprogressively warmer relative to a downward direction of reference; theimprovement comprising: at least one passage means descending from thecoolant compartment and adapted to receive a gravity flow of gasifiedcoolant; and a plurality of vertically spaced apertures branching fromthe descending passage means and individually communicatIng withindividual ones of said product compartments; the sizes of the inletmouths of said apertures increase progressively relative to a downwarddirection of reference such that said apertures divide said gravity flowof gasified coolant into increasingly larger portions relative to adownward direction of reference, to maintain the temperatures of saidproduct compartments substantially uniform.
 2. A cooling container asdescribed in claim 1 wherein: an upright baffle plate is located at anupper portion of said descending passage means and is operable toprovide a constricted entrance into the uppermost product compartment.3. A cooling container as described in claim 1 wherein: said descendingpassage means, at its lower end, and at a location shielded from saidapertures, is operable to collect and drain condensate.
 4. A coolingcontainer as described in claim 1 wherein: said coolant comprisesparticuted, solidified carbon dioxide.
 5. Apparatus according to claim 1wherein said transportable cooling container has support wheels, sidewalls, and front and rear ends spaced in the direction of containertravel; said passage means extending laterally across and verticallyalong said rear end; at least part of said coolant compartment beinginclined relative to horizontal toward said descending passage means tofacilitate gravitational flow of coolant gas thereto; the aperturesdisposed beneath the uppermost product compartment including guidetongues extending outwardly and upwardly from their respectivecompartments and into said descending passage means; the horizontallocations of said tongue-including apertures being generally staggeredrelative to a vertical direction of reference to minimize the extent towhich the flow of cooling gas into said apertures is impeded.
 6. Acooling container as described in claim 1 wherein: said descendingpassage means extends essentially over the entire height of thecontainer and reaches across one side of the container; said descendingpassage means is bounded on one side by an outside wall means of thecontainer and on another side by a separating wall means extendingessentially parallel to the outside wall means; and said separating wallmeans has sluice-like apertures, each leading to an individual productcompartment.
 7. A cooling container as described in claim 6, wherein:said sluice-like apertures comprise openings in the separating wallmeans and guide tongues extending from individual apertures andprojecting from the separating wall means into the descending passagemeans at progressively greater angles of inclination along a downwarddirection of reference.
 8. A cooling container as described in claim 7,wherein: said container includes a door, located on a narrow side ofsaid container; said door being operable relative to said compartments;said descending passage means is disposed on a side of said containeropposite said door; and said descending passage means is disposed incommunicating relation with vent means communicating with the exteriorof said container.
 9. A cooling container as described in claim 8,wherein: said coolant compartment supports a coolant inclined inrelation to the horizontal in such a way that it slopes downward towardsaid descending passage means.
 10. A cooling container as described inclaim 9, wherein the entire container, including said coolant andproduct compartments, has a downward slope, inclined downwardly towardsaid descending passage means.
 11. A cooling container as described inclaim 1 wherein: said descending passage means comprise shaft meansprovided on opposite ends of the container; and at least an upper one ofsaid product compartments includes vent means communicating with theexterior of said container and located on sides of said containerextending between said narrow sides.
 12. A cooling container as in claim11, wherein: said coolant compartment supports Coolant inclineddownwardly toward respective ones of said shaft means to facilitategravitational flow of said cooling gas toward said respective shaftmeans.
 13. A cooling container as described in claim 12, wherein: eachof said shaft means is defined, at least in part, by spaced wall meansof door means of said container.
 14. A cooling container as described inclaim 1 wherein: an aperture communicating with the uppermost productcompartment may be selectively closed; and said uppermost productcompartment is operable to be selectively vented to the exterior of saidcontainer.
 15. A cooling container as described in claim 14, wherein:said container includes an insulating plate disposed between saiduppermost product compartment and said coolant compartment.
 16. Acooling container as described in claim 1 including: movable closuremeans for said apertures located beneath the uppermost productcompartment; coolant flow control means operable to operate said closuremeans to control flow of gasified coolant through said apertures inresponse to the temperatures of the respective product compartmentcommunicating with said aperture.
 17. A cooling container as describedin claim 16, wherein: a plurality of said closure means areinterconnected such that said coolant flow control means is operable tosimultaneously control the flow of gasified coolant through saidplurality of said apertures.